Windows 10: Random reboots and "Invalid System Disk" message

I wasn't sure where this goes so I'm posting in General. My W10 machine, which I built right after Christmas 2018, is having random reboot issues that I can't figure out. At random times the machine will reboot, and then show a black screen with the message "Invalid System Disk. Replace the Disk and Press Any Key". Pressing a key then boots W10 normally.

It's starting to become an issue because it happened last night while my son was in the middle of his distance virtual learning school work, causing him to have to re-enter answers to several questions.

I have perused the Event Logs after one of these random reboots, but I can't really seem to find anything useful that would indicate would might cause the machine to reboot. And why would it say "Invalid System Disk" and yet still boot normally?

Actually it may have USB set as a boot device before the internal nVME SSD, which would explain the Invalid System Disk if my son's school flash drive is in the machine when it boots. But that still doesn't explain the random reboots the machine is doing.

At one time I thought the power supply might be an issue, because I built the machine with a PSU from a previous build. I replaced the power supply a few months ago, but obviously that wasn't the cause because it's still happening. So aside from checking the boot order in BIOS, anything else I might check that would explain these random reboots?

Machine is currently on Win10 Pro 1909.

:)

 

Invalid System Disk

Iam trying to flash my video card with a different bios for my radeon 9600, i followed some tutorial and made a bootable floppy and put FlashRom and the bios in it but when i try to boot with it is says Invalid System Disk.
Is there anyway to fix this ?
Also my motherboard is Asus P5P800 if that would help.

 

Random Reboots

I've had, as the title suggests, random reboots for the length of the time since I've built my computer (2 years roughly) and they're completely inexplicable.

It happens under no load, high load, watching movies, listening to music, playing games, browsing the web, sitting by itself in the room when the my sleeping monitor is even saying WTF?!

There aren't any Events to view other than the usual 0xC*D event when the service just shrugs at me.

Any thoughts or suggestions? Maybe someone has had the same problem before and it was just a loose molex connection? I'm baffled.

 

Reboot random in my PC

Hi Diego,

We need to gather more information for us to better assist you on your random reboot concern. Kindly answer the following:

• When did the random reboot issue start?
• Were there any changes made on your computer before encountering the issue?
• Are you encountering a blue screen error when your computer suddenly reboots? If so, what is the error message that you're getting?